VIBRATION STUDIES ON COMPLETELY FREE SHALLOW SHELLS HAVING TRIANGULARAND TRAPEZOIDAL PLANFORMS

The first known vibration study on completely free shallow shells havi ng triangular and trapezoidal planforms is conducted. The Ritz method with algebraic polynomials is used. Detailed convergence studies are m ade and showed that relatively accurate results can be obtained. The l owest six natural frequencies for completely free shallow shells with triangular and trapezoidal planforms are listed. Both right and symmet rical triangular and trapezoidal shell configurations are considered. The methods can be used for generally shaped planforms.